GB1423830A - Gauging of heat flux - Google Patents

Abstract

1423830 Measuring heat flux BABCOCK & WILCOX Ltd 27 Feb 1974 [27 Nov 1972] 54745/72 Heading G1D Heat flux impinging on a region of a combustion chamber is gauged by temporarily positioning a probe 6 at the region of the chamber so that a surface 8 of heat-conductive material forming the probe becomes exposed to the heat flux and obtaining a measure of the rate of heating up of the probe 6 when so positioned. The probe 6 may comprise a cylindrical slug of copper having a thermocouple located therein and surrounded by a mica layer 11 and a stainless steel tube 12. The tube 12 having vents 24 houses a tube 22 for supplying compressed air to a nozzle 21 which is directed towards the probe 6 for cooling purposes, the tube 12 being surrounded by a plurality of radially spaced tubes Fig. 2 (not shown) having vent holes (41), and connected by way of a tube 14 and a coupling to control apparatus, Fig.5. The control apparatus comprises an electric circuit provided with relays (I and II), "start" and "cancel" switches (51, 52), switches operated by the relays, switches operated at predetermined temperatures sensed by the probe 6, a magnetic clutch W for a timer Y, a device U for activating the compressed air and warning lamps (53, 54, 55). With the probe 6 below a predetermined base temperature at which switch (LL) is closed, the start switch (51) is temporarily closed so that relay (I) becomes energized and, as a consequence of switch (I/I) closing, remains energized. Relay (II) becomes energized when the start switch (51) is released. The probe 6 is now inserted into the chamber. Upon rising to a predetermined first temperature, switch (L) completes the timer circuit until switch (H) closes to 104 at a second, higher, temperature. The timer then stops, relay (I) becomes de-energized to close (1/2) and the device (U) is activated to supply compressed air to the nozzle 21 to cool the probe 6. The probe 6 is removed from the chamber and cooling is effected until the probe 6 is at a temperature below the base temperature. The timer Y may be read before the switch 51 is depressed again. Upon depressing the switch 51, switch S/1 is opened to de-energize relay 11 and the magnetic clutch W so that the timer pointer, drivable by the clutch W,.can return to zero. The device U also becomes de-energized.